Benthic-Pelagic coupling describes the exchange of energy, mass, nutrients, etc. from the benthos to the pelagic zone and vice versa. The benthos and the pelagic zone are areas or habitats in aquatic ecosystems. The benthos is the sea floor, the pelagic zone is the water above the seafloor. The pelagic zone is divided into many different zones dependent on depth. The filter feeders of the benthos take in anything that is suspended in the water column, organic matter, nutrients, etc. One of the more abundant and important of the filter feeders are the porifera, or sea sponges. These and other filter feeding benthic biota act like kidneys that filter the sea water to remove the nutrients they are after, but also other particles in the water column. Some of these particles could be hazardous to the organisms.

Porifera and other filter feeders are crucial for the cycle of nutrients in these ecosystems. They take in nutrients that have been dissolved into the water column, from the seafloor or elsewhere. Additionally, poriferans take in organic matter from deceased organisms such as plankton. According to Amanda Kahn and Sally Leys in their article,

The figure shows a choanocyte locating and inserting itself into a choanocyte chamber.

Porifera, and other filter feeders, help to prevent the saturation of nutrients, carbon, and other material in the water column. Keeping these materials in check help to prevent algal blooms and ocean acidification, via the degradation of biomass that produces carbon dioxide.

3 Comments

Great article! The importance of sponges in marine ecosystems is often underestimated. (Just make sure you fix some of those links- and linking to text instead of using numbers might be more reader friendly 🙂 )